FACTOIDS & TRIVIA
The Ampeg M-15 was introduced in 1959 and had a circuit that is very similar to the M-12 Mercury, except that the former has a 15-inch speaker and runs at higher voltages with a 5U4GB rectifier and pair of 6L6GC power tubes. As would be expected, the M-15 sounds similar to the M-12, but has a fuller sound with more bottom end. The Big M is well suited for rock and blues and takes effects pedals well. In fact, Ampeg named it "Big M" which seems to mean "Big Mercury". Interestingly, the name was not applied to the M-15's control panel until 1963 and lasted up to its discontinuation in 1965. The amp shown here is a testament to how good this model sounds because it has been played! The handle and grill are not original and the Jensen has been given a rest by a substitute Jupiter 15LC speaker. And it sounds great!
AMPEG BIG M M-15 (March 1961)
Power Amp: Tube; 2 x 6L6GC, 25 watts RMS @ 8 ohms
Preamp: Tube; 3 x 6SL7
Rectifier: Tube; 1 x 5U4GB
Speakers: 1 x 15" Jensen C15N
Channels: 2; 2 inputs for Channel 1 (Instruments), 1 input for Channel 2 ( Accordion), 1 stereo input
Effects: Tremolo
Controls: Volume and tone for each channel, tremolo intensity and speed, foot switch for tremolo
Dimensions: 21 H x 201/2 W x 12 D inches
Weight:
40 lb